THE NITRONE SPIN TRAP DMPO SWITCHES MACROPHAGE TOWARDS M2-LIKE ANTI-INFLAMMATORY PHENOTYPE

MUNOZ, MD; ALVAREZ, SE; SANDRA E GOMEZ-MEJIBA; RAMIREZ DC

BOSTON, MA

Congreso; 22ND ANNUAL MEETING OF THE SOCIETY FOR FREE RADICAL BIOLOGY AND MEDICINE; 2015

SFBRM

Marcos D Munoz1 , Sergio E Alvarez1 , Sandra E Gomez Mejiba1 , andDario C Ramirez11CONICET, UNSL, San Luis, ArgentinaThe search for mechanism-based therapeutics against chronicinflammation (CI) is a highly desired focus of pharmaceuticalindustries. The switch of macrophages phenotype from a normalM2-like towards an inflammatory M1-like phenotype is known toplay an important pathogenic role in a number of CI diseases.Previously we found that the nitrone spin trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO) besides being an efficient and cellpermeable spin trap can produce anti-inflammatory and insulinsensitizing effects in models of diet-induced obesity. Although,many of the spin trapping properties of DMPO have beenextensively investigated, the information regardingpharmacological effects of this spin trap is more limited. Hereinwe aimed at digging into the molecular mechanism by whichDMPO reduce inflammatory activation of macrophages. Toapproach this aim we used a well-known model of RAW264.7-macrophage-like cells treated with 1 ng/ml lipopolysaccharide(LPS) with or without 50 mM DMPO and found that DMPOdamped LPS-induced activation of inflammatory gene expressionand cytokine production. Trasncriptomics (microarray),proteomics (iTRAQ) and Ingenuity Pathway analyses suggest thatDMPO damped LPS-distinctive transcriptome profile ofinflammatory mediators by switching transcription factors involvedits cell response. LPS activates NF-kB and IRF-7 signalingpathways that cause an M1-like phenotype of macrophages.When these cells are pretreated with DMPO, it causedsignaling/transcriptome/proteome changes to give a typical M2-like phenotype that is resistant to LPS-induced activation. DMPOtriggers an anti-inflammatory and antioxidant-PPAR-d/Nrf-2-dependent M2-phenotype. Taking together our data suggest thatthe anti-inflammatory effects of DMPO on macrophage is due to aswitch on signaling, transcriptome and proteome towards an M2-like phenotype.Support: PICT-2014-3369, PROICO-2-3214 and PROICO10-0414.